Cuprous complexes



United rates 3,051,736 CUPROUS COMPLEXES Christian F. Horn, SouthCharleston, W. Va., assignor to Union Carbide Corporation, a corporationof New York No Drawing. Filed Dec. 27, 1960, Ser. No. 78,250 4 Claims.(Cl. 260438) This invention relates to novel cuprous complexes. Moreparticularly, this invention relates to novel, stable,cyclohexenecarbonitrile cuprous complexes useful in aiding the dyeing ofacrylonitnile fibers.

It is known in the textile field that synthetic fibers composed ofacrylonitrile interpolymers are extremely difficult to dye. To overcomethis difiiculty, a copper dyeing method was proposed wherein dyeingoccurred in the presence of cuprous ions. Satisfactory dyeing resultsare obtained using the above described process; however, there are somecharacteristics of this process which make it less desirable when usedin large scale dyeing. When the cuprous ion is produced in the dye bathby the reaction of copper compounds, such as copper sulfate, andreducing agents, several deficiencies arise. These deficiencies centeraround the reduction of the cupric ion to to the active cuprous ion. Ifthe rate of reduction is not carefully controlled, two undesirableoccurrences may result. Initially, if the cupric ion is not fullyreduced, the chemicals in the bath will be unsatisfactory for use in thedyeing process. On the other hand, if the cupric ion is over-reduced,metallic copper may be present in the bath which will impair both lightstability and the color shade of the fiber. In addition, theabove-described problems make the dyeing formulations extremelydifiicult to reproduce. It is the combination of these problems whichhave discouraged the use of the cuprous-ion technique. There hastherefore been a long felt need in the art for a stable cuprous-ioncomplex which could be added directly to the dyebath without goingthrough the reduction process.

I have discovered a class of novel, inorganic acid salts of cuprouscomplexes of cyclohexenecarbonitnile which are stable and which can beused to provide outstanding results in the cuprous-ion dyeing technique.A distinct advantage of the compounds of this invention pertains to thefact that not only are the cuprous complexes of cyclohexene-carbonitrilea dyeing aid in acid dyes but also in the dyeing process, thecyclohexenecarbonitrile molecules act as dye carriers. Thus very deepcolor shades of the dyed fabric can be obtained in the use of thecompounds of this invention without the addition of conventional dyecarriers.

The cyclohexenecarbonitrile portion of these complexes can berepresentedby the general formula:

wherein each R, individually, represents a hydrogen atom or an alkylradical, preferably containing from 1 to 6 carbon atoms.

The cyclohexenecarbonitriles which are used to prepare the novel cuprouscomplexes of this invention include, for example:3-cyclohexenecarbonitrile, 2-cyclohexenecarbonitrile,l-cyclohexenecarbonitrile, 2-methyl-3-cyclohexenecarbonitrile,3-ethyl-3-cyclohexenecarbon-itrile, 5-n-hexyl-3-cyclohexene-canbonitrile,2-isopropopyl-2-cyclohexenecarbonitrile,5-ethyl-2-cyclohexenecarbonitrile, 4-nhexyl-Z-cyclohexenecarbonitrile,3-isopropyl-l-cyclohexenecarbonitrile,Sal-hexyl-l-cyclohexene-carbonitrile, and the like.

The cuprous salts which are preferably used in the production of thecuprous complexes of this invention include the cuprous salts such as,for example, cuprous chloride, cuprous bromide, cuprous iodide, cuprousnitrate, cuprous sulfate, cuprous phosphate, and the like.

The novel cuprous complexes of cyclohexenecarbonitrile can be readilyproduced by reacting the cuprous salts such as, for example, cuprouschloride, with a cyclohexenecarbonitrile such as, for example,3-cyclohexenecarbonitrile at a temperature of from about 20 C. to about100 C. for a period of time suflicient for the cuprous complex to formand dissolve in the reactant solution. The reaction can be conducted inan inert organic reaction medium which has a function of a solvent inthe event that the cyclohexenecar bonitrile star-ting material is asolid at room temperature. The time of reaction can range from a fewminutes to as long as 24 hours depending on the reaction temperature andthe specific reactants used. In general, when the cuprous salts areadded to the cyclohexene-canbonitrile to produce the products of thisinvention, the resulting reaction is exothermic. The temperature iscontrolled and prefer-ably maintained in the range of from about 40 C.to about C. After the initial exothermic reaction has run its course,additional heat can be applied to maintain the temperature and completethe reaction more rapidly.

In producing the novel cuprous complexes of cyclohexenecarbonitrile thecyclohexenecar-bonitrile is preferably employed in mole ratios greaterthan the equivalent amount of cuprous salt present. The preferred rangeis from about a 1:1 to 1:4 mole ratio of cuprous salts tocyclohexenecarbonitrile. Higher or lower ratios are operable; however ahigh excess of cyclohexenecarbonitrile is not economically feasible andlower ratios do not make full use of the cuprous salts charged.

In producing the novel cuprous complexes of this invention, it isdesirable, although not necessary, to conduct the reaction in anatmosphere of an inert gas free of elemental oxygen, such as anatmosphere of nitrogen, carbon dioxide, helium, and the like. The inertatmosphere aids in decreasing the possible air oxidation of the cuproussalts to the undesirable cupric salts although the cuprous complexes ofcyclohexenecarbonitrile can be produced in the presence of air.

Among the cuprous complexes of this invention which can be produced bythe above described process are, for example: complex of cuprouschloride and 3-cyclohexenecarbonitrile, complex of cuprous chloride andZ-cyclohexene-carbonitrile, complex of cuprous chloride and 5-n-hexyl-3-cyclohexenecarbonitrile, complex of cuprous chloride and2-isopropyl-3-cyclohexenecarbonitrile, complex of cuprous bromide and3-cyclohexenecarbonitrile, complex of cuprous bromide andS-n-hexyl-l-cyclohexenecarbonitrile, complex of cuprous nitrate and2-cyclohexenecanbonitrile, complex of cuprous nitrate and 1-cyclohexenecarbonitrile, and the like.

The cuprous complexes of the invention can be recovered from theirreaction mixtures in high purity by cooling the reaction mixture toprecipitate the cuprous complex and isolation by conventional filtrationprocedure. If the cuprous complex reaction product does not crystallizeon cooling, the reaction product can be precipitated by the addition ofan organic non-solvent such as acetone, ethyl ether, ethyl acetate,dioxane, and the like. If additional purification of the coppercomplexes is desired, Conventional recrystallization pro-- cedures canbe used.

The following examples are illustrative:

Example 1 Cuprous chloride (10 grams) was added portionwise withagitation to 54 grams of 3-cyclohexenecarbonitrile in a nitrogenatmosphere. The reaction was exothermic, raising the temperature fromabout 20 C. to 35 C. during the addition. After completion of theaddition of the cuprous chloride, the reaction mixture was kept at 75 C.for 4 hours. The reaction mixture was filtered warm and stored overnightin a refrigerator at a temperature of approximately 10 C. where thereaction mixture crystallized to a solid mass. The reaction mixture waswarmed to room temperature and the solid was filtered, the filter cakewas recrystallized from acetone, dried at room temperature and analyzedto be the desired cuprous chloride complex of 3-cyclohexenecarbonitrile.-It melted at 7 274 C.

The'infrared spectrum and analytical data confirmed the structure as 2CH CN+C11CL In an analogous manner, -n-hexyl-3-cyclohexene-carbonitrileis reacted with cuprous nitrate to obtain the corresponding cuprousnitrate complex of 5-n-hexyl-3- cyclohexenecarobnitrile. Additionally,2-cyclohexenecarbonitrile is reacted with cuprous sulfate to obtain thecorresponding cuprous sulfate complex of 2-cyclohexenecanbonitrile.

Example 2 A 5 gram sample of scoured and dried knitted tubing ofcontinuous yarns composed of a terpolymer of acrylonitrile; vinylchloride and vinylidene chloride [in a ratio, respectively, of 70:20:10]was added to a 200 milliliter total Volume aqueous dyebath containing 1percent by Weight of the yarn of Pergegal OK (a cationic condensationproduct of ethylene oxide and an organic amine marketed by GeneralAniline and Film Corporation), 2 percent by weight of the yarn ofconcentrated sulfuric acid, 3 percent by weight of the yarn of XyleneMilling Blue G.L. (Acid Blue 1 02-50315) and 3.0 percent by weight ofthe yarn of the cuprous chloride complex of 3-cyclohexenecarbonitrile.The cuprous chloride complex of 3-cyclohexenecarbonitrile was added as amixture of 5 parts by weight of acetonitrile to 1 part by Weight ofcuprous chloride complex of 3-cyclohexenecarbonitrile. The bathtemperature was raised to boiling in about 20 minutes and held for 90minutes at the boiling temperature. The dyed fabric was then raised,scoured, rinsed, hydroextracted and dried at 130 C. for 10 minutes.After drying, the dyed fabric had a final K/S* value of 12.9. The commonFade-O-Meter test indicated a light fastness rating of the dyed fabricof 40 hours.

What is claimed is:

1. The cuprous complex produced by'the reaction of a cuprous salt of aninorganic mineral acid with a cyclohexene-canbonitrile of the formula:

wherein each R, individually is selected from the group consisting ofhydrogen and the alkyl radicals of from 1 to 6 carbon atoms, at atemperature of from about 20 C. to about C.

2. The cuprous complex produced by the reaction of cuprous chloride with3-cyclohexenecarbonitrile at a temperature of from about 20 C. to about100 C.

3. The cuprous complex produced by the reaction of cuprous nitrate with5-n-hexyl-3-cyclohexenecanbonitrile at a temperature of from about 20 C.to about 100 C.

4. The cuprous complex produced by the reaction of cuprous sulfate with2-cyclohexenecarbonitrile at a temperature of from about 20 C. to about100 C.

No references cited.

The amount of dye on fiber or the depth of color are approximately proortional to the K/ S value which is a. measure of the light re eetedfrom the dyed sample. The larger the K/S value, the deeper the shade;and a K/S value of 20 is approximately twlce as deep as a. K/S value of10. The determination of the K/S values is set forth in an article by D.B. Judd, Color in Business, Science and Industry, 1952, pp. 314-342. V

1. THE CUPROUS COMPLEX PRODUCED BY THE REACTION OF A CUPROUS SALT OF ANINORGANIC MINERAL ACID WITH A CYCLOHEXENE-CARBONITRILE OF THE FORMULA: